Regulating valve



May 23, 1950 3 7 .V 7 0 Z 5 n a 6 6 9. 6a my 7 0 f a N M7 m g HQ 1 m 5 m mm INVENTOR AMT/MA P. GLE/VNY B y M AZTTORN EY Patented May 23, 1950 REGULATING VALVE Arthur Philip Glenny, Hanworth, England, assignor to The Sperry Gyroscope Company,Ltd.,

Brentford, England Application May 2'7, 1946, Serial No. 672,638 In Great Britain June 4, 1945 lators for maintaining a substantially constant fluid pressure in a system to be supplied with pressure fluid from a variable pressure source and more particularly to regulators in which this obfleet is achieved by throttling the supply of fluid by means of a reducing valve connected between the source and the system.

The invention is applicable whether the variations from the pressure to be regulated in the system are due to changes in the pressure source or to changes in the system itself, as, for instance, theaddition of further apparatus.

: In some previously known regulators a reducing valve of the piston type has been used to throttle the supply of pressure fluid, said valve being under the control ofa diaphragm responsive to the pressure supplied from the pressure source and a spring being employed to bias the valve to or towards an open position. In this arrangement one side of the diaphragm is connected to atmosphere and the other side to the supply pressure, so that, under normal circumstances, the output pressure is determined by the valve taking up a position such that the difference in pressure on the two sides of the diaphragm balances the force exerted by the spring. If the supply pressure increases, the pressure, difference on the diaphragm increases and acts to close the valve, against the spring influence, thereby throttling the flow to a 3 Claims. (Cl. 50--26) which'it'is desired to keep constant. Under these circumstances the regulation achieved cannot be regarded as wholly satisfactory.

A further disadvantage in these known regulators is that the springs are usually enclosed within the body of the apparatus which must therefore, be dismantled when it is necessary to replace the spring or adjust itsinitial stress or pressure.

It is, accordingly, one of the objects of the present invention to provide a pressure regulator in which greater accuracy of regulation than has been attained heretofore can readily be achieved. For this purpose the invention provides a regulator in which the extent of movement of the spring is small compared with the extent of move ment of the throttling valve and also compare greater extent and ensuring that the increased supply pressure is not effective on the output side of the said valve and so will not be passed on to the system. If the supply pressure decreases, the pressure difference on the diaphragm decreases and the spring acts to open the valve, thereby throttling the flow to a smaller extent.

In pressure regulators of the kind described, when the sup-ply pressure varies there is also a variation in the output pressure, though one of smaller magnitude. Since the pressure difference on the diaphragm is always balanced by the spring pressure, the degree to which the spring pressure varies will depend on the degree to which the output is stressed for different positions of the throttling valve corresponding to the different degrees of throttling required for different supply pressures.- In the previously known arrangements, the spring acts directly on the piston valve and accordingly has the same range of movement as that valve. Also, in order to obtain a compact,

design, the springs in these known regulators are made relatively short, so that the maximum movement of the piston valve, and, consequently, the maximum operational distortion of the spring amounts to a not inconsiderable fraction of the length of the spring. The variation in spring stress and, consequently, the variation in the output pressure amounts, therefore, to a considerable fraction of the initial stress in the spring 1. e. to'a substantial proportion of the output pressure with the length of the spring.

It is a further object of the invention to provide a compact design of regulator in which the spring is located in an easily accessible position in order to facilitate replacement of the spring or adjustment'of its initial stress.

In accordance with one of the several features of the invention, there is provided a pressure regulator for regulating the fluid pressure in a system which is supplied from a supply source and is liable to fluctuations arising either from the supply source or from changes in the system itself, said regulator comprising communicating means through which said fluid is passed from said source to said system, throttling means adapted to obturate said communicating means to a variable extent, in order, to vary the flow of pressure fluid through said communicating means, means responsive to the pressure in the system for urging said throttling means in one direction and resilient means operating through a linkage device to urge said throttling means in the opposite direction, the linkage device being such that any deflection or distortion of the resilient means under the influence of said pressure responsive means is smaller than the co-related movement -of said throttling means.

It is to be clearly understood that the present invention is applicable to systems employing either positive or negative pressure.

There will now be described, with reference to the accompanying drawings, one embodiment of the invention from which the above mentioned and other features will become apparent. It is to be appreciated, however, that the said embodiment is selected for description merely by way of illustration of the invention and not by way of limitation thereof.

In the said drawings Figure 1 shows the device in sectional elevation, the section being taken on line I-I of Figure 2, which latter is a plan view of the said device. Figure 3 is an elevation taken at right angles to Figure 1 and looking in the direction of arrow III.

The embodiment selected for description is one 3 for use where the source of supply provides negative pressure or suction. It comprises a, main casing formed of the parts I and 2, which are fastened together by means of bolts 3. The lower part 2 of the casing is traversed by a horizontal passage flexible diaphragm 5 which is peripherallyclamped in said casing by the bolts 3, aforesaid. Passing through the upper and lower walls of the two compartments and into the passageway in the lower part ofthe casing is a vertical tubular plunger fi whose lower end Ea serves to obstruct variably thepafssagew'ay 4 and thus acts as a piston throttiing the amount of fiuid passing therethrough. A fixedly located plug 1 having a fiat face In. confronting the end 8d of the plunger 6, partakes in the throttling action. The plunger 6 also passes through and is rigidly connected to thediaphragm 5. This latter is strengthened bymeans of a plate 8 resting on a flange 6b ofthe plunger, which is threaded to receive a nut 9, whereby the said diaphragm is secured firmly against said plate. The upper compartment la of the casing has a leak It] to the surrounding atmosphere, while a hole II in the lower wall 22 of the lower compartment it; puts the latter into communication with the passage way 4 on that side of the plunger which is remote from the source of supply. I v V V g V The tubular plunger (5 is adapted to be pulled upwards by means of :fleiiible wire I2 which passes through it and this wire has a nipple 12a at its lower end, which nipple engages with an inner 'web of the said plunger. The upper end of the wire [2 also has a nipple l2b which engages with the end of the horizontal arm [3a of a cranked lever l3 which is pivoted on a knife edge [3b in a seating l4 located in an extension lb of the upper half or the valve casing. The other arm 130 of the lever I3 is much shorter than the horizontal arm and it extends upwards through an opening in the wall of a horizontal tube I 5, which houses a spring-urged plunger l6 and is mounted in an auxiliary casing or superstructure l1, screwed to the casing part i, la. The spiral compression spring 13 acting through the plunger l6 and, thence through a horizontal push rod l9 (co-axial with saidspring l8 and said tube 15) exerts a thrust on theend oi the short arm l3c of the lever l3. An abutmerit for said spring I8 is provided by a plug which is screwed adjustably into one end, of the tube [5. The spring pressure and, thus, the force exerted on the members It, l9 and I3 can be regulated by adjusting the position of the screw plug 20 in the tube l5 to vary the regulated pressure maintained by the valve.

The above described embodiment of a valve according to the present invention is particu-' larly designed for use with an air-driven instrumerit, a vacuum pump being used to suck air through the instrument; In this particular embodiment the side 42) of the passageway 4 is connected to the instrument, the leak II from the passageway to the compartment 2a being located on the instrument side of the plunger 3. The other side 4d of the passageway is connected to the vacuum pum'p.

In operation the vacuum pump draws air through the passageway 4 from the system through which a now of air is to be maintained 4 and the vacuum pressure is communicated via the leak II to the underside of the diaphragm t. This latter is, therefore, tuned downwards. carrying the plunger 6, down into the passageway, against the action of the spring 18, until a state of equilibrium is reached when the suctionbalances the spring force acting through the ever l3. If, new, for any reason, such as the additionof iiiither apparatus to the system and a consequent increase in the flow of air thrsiigli the passageway, the vacuum falls, the reduced suction communicated to the underside of the diaphragm permits the spring to move the plunger 6 upwards, to open the passageway until a state of balaneisreached again at a pressure close tothe original. Similarly, if, for any reason, the new of air mouse the passagef need-eased, the will increase and raw the diaphragm an theplung r a clownwards, to decrease the flow oi arm-rough the s aidpas sag'eway until a state (if balance is reached. i

It will readily be apparent that the loss the spring force varies -during fip'er'atiori, the more nearly will the suction on the instrument re manner the cohtrblled amount, determined by the said spring fares as set bythe s'crew plug. The lever ratio t e present e 351) ensures that the fnovement of the spr ng I8 is kept smaller than the movement (it the plunger 6; hence the spring force is rest mere uniform than if the spring were acting directly on the said plunger.

I claimi a l. A n1 ativ pressure prising a housing h V hells, a valve in said Q llSll'i g" between said chain p n for throttlitlg the fluid passing there through, pressure responsive means operatively connected to said valve, 5; port insaid housing connecting one of said cheeses and the pressure responsive means, a secohd port in said housing eonriectihg said pressure responsive ineaiis to the atmosphere, said pressure responsive means being operable to arge said valve towards a elosed position, and means for c'ouhterbalahcing the iorce of said pressure responsive rnahs tend; ing to c'ltise said valve including a lever in saitl housing having a leverage ratio of app ioxi mately three to one, a tension ember connecting the long arm of the lever ai'id said valve, and a spring anchored at one end to said housing and connected at its other end to the short arm of the lever; a p

2; A regulator as names in claim 1, in which Samara port amete the pressure iesptnsae means and said inlet eliani'iel.

3. A regulator as claimed in ,n 'nh. ARTHUR PHILIP GLENNY.

harshness oiran 'i'ri roiitwing reisreiiees are of record in the file of this patent:

UNITED seams messes 

